Urea derivatives of furfuryl and pyranylmethyl compounds

ABSTRACT

WHEREIN R is 2-furyl, 2-tetrahydrofuryl, 3,4-dihydro-2H-2pyranyl, or 2-tetrahydropyranyl; R&#39;&#39; is hydrogen or C1-C3 alkyl; R&#39;&#39;&#39;&#39; and R&#39;&#39;&#39;&#39;&#39;&#39;are hydrogen, methyl, or methoxy; or NR&#39;&#39;&#39;&#39;R&#39;&#39;&#39;&#39;&#39;&#39; may form an aziridino, pyrrolidino, piperidino, or morpholino ring; and R&#39;&#39;&#39;&#39;&#39;&#39;&#39;&#39; and R&#39;&#39;&#39;&#39;&#39;&#39;&#39;&#39;&#39;&#39; are hydrogen, C1-C6 alkyl, C1-C6 alkoxy, C1C6 alkylthio, C1-C6 alkylsulfinyl, C1-C6 alkylsulfonyl, chloro, bromo, fluoro, trifluoromethyl, cyano, nitro, phenoxy, halo substituted phenoxy. These compounds are useful as herbicides.   There are provided compounds having the formula:

United States Patent [191 Maravetz Jan.7,1975

[ 1 UREA DERIVATIVES OF FURFURYL AND PYRANYLMETHYL COMPOUNDS [75] Inventor: Lester L. Maravetz, Westfield, NJ.

[73] Assignee: Mobil Oil Corporation, New York,

[22] Filed: June 20, 1972 [21] Appl. No.: 264,696

[52] U.S. Cl 260/347.3, 260/345.7, 260/247.2, 260/293.67, 260/3263, 71/94, 71/95, 71/88 {51] Int. Cl. C07d 5/14, C07d 7/10 [58] Field of Search 260/3473, 345.7

[56] References Cited OTHER PUBLICATIONS Tiwari et al., Chem. Abstracts, (1963), Vol. 66, 3450 Primary Examiner-l-lenry R. Jiles Assistant Examiner-Bernard I. Dentz Attorney, Agent, or Firm-Andrew L. Gaboriault; Hastings S. Trigg [57] ABSTRACT There are provided compounds having the formula:

wherein R is 2furyl, Z-tetrahydrofuryl, 3,4-dihydro- 2H-2-pyranyl, or 2-tetrahydropyranyl; R is hydrogen 6 Claims, No Drawings UREA DERIVATIVES OF FURFURYL AND PYRANYLMETI-IYL COMPOUNDS BACKGROUND OF THE INVENTION SUMMARY OF THE INVENTION This invention provides compounds having the formula:

RI! CHN-CN/ O R!!! wherein R is 2-fury1, Ltetrahydrofuryl, 3,4-dihydro- 2I-I-2-pyranyl, or Z-tetrahydropyranyl; R is hydrogen or C -C alkyl; R" and R are hydrogen, methyl, or methoxy; or NR"R" may form an aziridino, pyrrolidino, piperidino, or morpholino ring; and R and R""' are hydrogen, C -C alkyl, C,--C alkoxy, C C alkylthio, C -C alkylsulfinyl, C -C alkylsulfonyl, chloro, bromo, fluoro, cyano, trifluoromethyl, nitro, phenoxy and halo-substituted phenoxy. It also provides the method of their use as herbicides and herbicidal compositions of these compounds on a carrier,

DESCRIPTION OF SPECIFIC EMBODIMENTS The compounds of this invention are ureas having N- furfuryl, N -tetrahydrofurfuryl, N-tetrahydro-2- pyranylmethyl, or N-3,4-dihydro-2I-I-2-pyrany1methyl substituent and phenyl ring-substituted derivatives as set forth in the structural formula hereinbefore. Examples of the compounds of this invention in addition to those specifically exemplified hereinafter are:

1,-1-Dimethyl-3-furfuryl-3-(3-ch1oro-4- methylthiophenyl) urea 1,1-Dimethyl-3-furfuryl-3-(3-chloro-4-methylsulfinylphenyl) urea 1,1-Dimethyl-3-furfury1-3-( 3-chloro-4- bromophenyl) urea 1,1-Dimethyl-3-furfuryl-3-(4-cyanopheny1)urea 1,1-Dimethyl-3-(tetrahydro-Z-pyranylmethyl)-3-( 3- 4-dichlorophenyl)urea 1,1Dimethyl-3'(3,4-dihydro-2H-2-pyranylmethyl)- 3-(3,4-dichlorophenyl)urea 1,1-Dimethy1-3-(3,4-dihydro-2H-2-pyranylmethy1)- 3-(3-trif1uoromethy1phenyl)urea 1,1-Dimethy1-3-tetrahydrofurfuryl-3-( 3-chloro-4- mcthylsulfonylphenyl)urea l-Mcthoxy-1-methyl-3-furfuryl-3-(3,4-

dichlorophcnyl)urea 2 1,1-Dimethyl-3-(a-n-propylfurfuryl)-3-(4- chlorophenyl)urea 1,1-Dimethy1-3-furfury1-3-(4-nitrophenyl )urea 1 ,1-Dimethyl-3-furfury1-3-(4-n-hexy1phenyl)urea 5 l,1-Dimethyl-3-fi1rfuryl-3-( 3-chloro-4-n-hexy1thiophenyl)urea 1,l-Dimethyl-3-furfury1-3-(3-ch1oro-4-n-hexyloxyphenyl)urea Y 1 ,1-Dimethyl-3-(tetrahydro-Z-pyranylmethyl)-3-(3- trifluoromethylphenyl)urea 1,1-Dimethyl-3-( 3 ,4-dihydro-2H-2-pyranylmethyl)- 3-(4-bromophenyl)urea 1 ,1-Dimethyl-3-(tetrahydro-2-pyrany1methyl)-3- (3,4-dimethylphenyl)urea 1-Methyl-3-(tetrahydro-Z-pyranylmethyl)-3-(3-trif1uoromethylphenyl)urea l ,1-Dimethyl-3-furfuryl-3-(3-t-butylphenyl)urea 1,1-Dimethyl-3-furfuryl-3-(3-chloro-4-nbutylphenyl)urea 1,1-Dimethy1-3-tetrahydrofurfury1-3-( 3-bromo-4-nhexylphenyl)urea 1 -Methoxy-1-methyl-3-furfury1-3-( 3-chloro-4- bromophenyl)urea 1,1-Dimethy1-3-furfury1-3-(4-phenoxyphenyl)urea 1,1-Dimethyl-3-furfuryl-3-(4-chlorophenoxyphenyl- )urea 1-Methy1-3-furfuryl-3-phenylurea 1,1-Dimethyl-3-furfury1-3-phenylurea 1 ,1-Dimethyl-3-furfury1-3-(3,4-dif1uorophenyl)urea 1,1-Dimethyl-3-furfuryl-3-(4-fluoro-3- nitrophenyl)urea V 1,1 Dimethy1-3-tetrahydrofurfuryl-3-( 2,5-

difluorophenyl)urea l, l -Dimethyl-3-furfuryl-3-(4-fluorophenyl )urea 1 ,1-Dimethyl-3-(tetrahydro-2-pyranylmethy1)-3-( 2- fluorophenyl)urea l,1-Dimethyl-3-furfuryl-3-(3-chloro-4- fluorophenyl)urea The compounds of this invention can be synthesized according to the equations below. I

I. Preparation of N-substituted anilines R\ RI!!! R!!! c=o +HzN A C=N RI/ RI'l/I H R Bill/I 5 0 I Hydrogenation R\ Rllf! CHNH RI/ RI/l RI!!! RCHzX HZN AH RIIIII R114! RCHzNH RIIIII R, R, R"" and R""' are as aforedefined. X=Cl,Br

R, R, R", R, R" and R"' are as aforedefined.

In the above synthesis, various tertiary amines, or inorganic bases may be used in place of the exemplary use of triethylamine, sodium hydroxide, etc., as stated in the equations above.

The intermediate imines as described in 1(a) above were prepared according to known techniques by condensation of appropriate aldehydes or ketones (e.g., Z-fur'aldehyde, 2-acetylfuran, etc.) with aromatic amines in refluxing benzene, xylene, or toluene. Azeoaniline 2brom0anilinc 2-chloroaniline 3chlorounilinc 4-chlornanilinc 3,4-dibromuanilinc 2,3-dichloroanilinc 3-bromoaniline 4bromoaniline 3-t-butylanilinc 3-mcthoxyanilinc 4-mcthoxyanilinc Z-mcthylanilinc 3-mcthylanilinc 3,5-dimcthylaniline 3-cthoxyaniline 4-eihoxyaniline 2-trifluoromethylaniline Z-methyl-S-cyanoaniline 3-trifluoromethylaniline 2-cthylaniline 3-t-butylaniline 3cthylaniline 3-chloro-4-methoxyanilinc 4-ethylaniline 3chloro-4-bromoaniline Z-iodoaniline 3-iodoaniline 4 iodoaniline 2-isopropylaniline 4-isopropylaniline 2-isopropyl-5-metliylaniline Z-methoxyaniline 3-chloro-4-fluoroaniline 2.5-difluoroaniline 3,4-difluoroaniline 4-fluoro3-nitroaniline 2-fluoroaniline 3-fluoroaniline 4-fluoroaniline Lisopropylaniline Lmcihylthioanilinc 4-cyanoaniline 3-chloro-4-methylthioaniline 3-chloro 4-methyisulfinylaniline 3-chloro-4-methylsulfonylaniline 4-nitroaniline 4n-hexylaniline 3-chloro-4-n-hexylthioaniline 3-chloro-4-nhexyloxyaniline 3-chloro-4-n-butylaniline 3-bromo-4-n-hexylaniline 4-phenoxyaniline 4-(4-chlorophenoxy)aniline The following examples illustrate thesynthesis of the imines. Y

EXAMPLE 1 N-Furfurylidene-3,4-dichloroaniline A flask was equipped with a condenser, stirrer, and Dean-Stark trap. The flask was charged with 3,4- dichloroaniline (50.0 g, 0.308m) and 700 ml of benzene. To this stirred solution was added 2-furaldehyde and the resulting mixture was refluxed overnight to yield 5.2 ml of water collected in the Dean-Stark trap. The reaction mixture was stripped of solvent under reduced pressure and the brown oily residue was extracted with hot petroleum ether (b.p. 30-60C). Chilling of the hot solution yielded tan solids which were filtered and dried (42 g; m.p. 3738.2C). The nuclear magnetic resonance and infrared spectra [IR (neat melt), C=N, 6.18 1,] substantiated the products structure as being N-furfurylidene-3,4-dichloroaniline.

EXAMPLE 2 N-(a-Methylfurfurylidene)-4-chloroaniline A mixture of 2acetylfuran (11.01 g, 0.1 m), 4- chloroaniline (12.76 g, 0.1 m), and molecular sieves (40 g, activated Linde type 5A, 60-80 mesh) in 55 ml of benzene was refluxed overnight with stirring.

The molecular sieves were filtered off, and fresh sieves (40g) were added tothe solution, which was again refluxed overnight. Removal of the sieves followed by stripping of the benzene under reduced pressure gave 19.3 g of red oil which consisted ofa mixture of product and starting materials. The oil was vacuum distilled up to a boiling point of 55C. at 0.45 mm which removed the unreacted acetylfuran and 4- chloroaniline. The residual oil (11.1 g) consisted of the desired product, and nuclear magnetic resonance and infrared spectra [lR, C=N, 6.17p.] were in agreement with the proposed structure.

The intermediate imines were reduced to the corresponding anilines either by use of sodium borohydride in methanol, sodium and alcohol, or magnesium and alcohol. N-tetrahydrofurfuryl anilines were obtained by catalytic hydrogenation of the corresponding N- furfurylanilines. The tetrahydro-Z-pyranylmethyl aniline was prepared by reaction of a substituted aniline with tetrahydro-Z-pyranylm ethyl bromide. The particular reduction technique employed is not a critical factor of this invention. The following examples demonstrate typical reduction reactions.

EXAMPLE 3 N-Furfury1-3,4-dichloroaniline N-Furfurylidene-3,4-dichloroaniline (42.0 g, 0.1735 m) was dissolved in 450 ml of absolute methanol. With stirring, solid sodium borohydride (7.8 g, 0.206 m) was added portionwise with the temperature being maintained between 35 and 40C. The reaction mixture was stirred overnight, and then refluxed briefly. Addition of 700 ml of water with stirring precipitated an oil which was extracted with benzene. The benzene extract was washed with water, dried with MgSO and evaporated down under reduced pressure to yield the product as an amber oil (39 g). Infrared analysis showed the absence of the C=N absorption at 6.18 1. and appearance of NH absorption at 2.9 2.

EXAMPLE 4 N-Tetrahydrofurfuryl-3,4-dichloroaniline A mixture of N-furfuryl-3,4-dichloroaniline (12.2 g, 0.05 m) and 5 percent rhodium/charcoal catalyst (0.6 g) in ml of absolute ethanol was hydrogenated in a Parr low pressure hydrogenation apparatus (initial pressure 60. psi). The theoretical uptake of hydrogen was achieved in about 8 hours whereupon the catalyst was removed by filtration. Concentration of the filtrate yielded 10 g of the product as an amber oil, which was homogeneous by glpc.

C. Synthesis of l-lerbicidal Agents The herbicidal agents of this invention may be prepared by several different methods:

I. By reaction of the N-substituted aniline with dimethylcarbamyl chloride using triethylamine or other tertiary anine as an l-lCl scavanger.

CHN

N O=iNHOCI-I:

(CHaO):S Oil NaOI-I 2NaCl CHN R co:

IV. By reaction of an N-substituted aniline with me- EXAMPLE 1 ,1-Dimethyl-3 furfuryl-3-(4-ch1orophenyl)urea A mixture of N-furfuryl-4-chloroaniline (6.0 g, 0.0289 In), triethylamine (3.8 g, 0.037 m) dimethylcar- 8 bamyl chloride (4.0 g, 0.037 m) and toluene ml) was refluxed overnight. After cooling, the reaction mix ture was stirred with 50 ml of saturated sodium bicarbonate solution for about /5 hour. The aqueous phase was removed and the residue washed consecutively with 10% HCl solution, saturated NaHCO solution. and water. After drying the solution with MgSO the solvent was removed under reduced pressure to yield a dark oil (5.3 g) which later crystallized. Recrystallization gave the product as a tan solid, mp. 96C.

EXAMPLE 6 l ,1-Dimethyl-3-furfuryl-3-(3 ,4-dich1orophenyl )urea A flask was charged with N-furfuryl-3,4- dichloroaniline (21.0 g, 0.086 m), triethylamine (8.7 g, 0.086 m) and benzene (500 ml). This solution was chilled with an ice bath during the dropwise addition of phosgene (8.5 g, 0.086 m) in benzene. The resulting slurry was allowed to stir at room temperature overnight after which the white solids were removed by filtration. The filtrate was transferred to another flask and gaseous dimethylamine (9.0 g, 0.2 m) bubbled into the solution. After stirring for one hour, the dimethylamine hydrochloride salt was filtered off, the filtrate was washed with 10% HCl solution, saturated NaHCO solution and water. Drying of the solution with MgSO followed by solvent removal gave a brown solid. Recrystallization from heptane gave the product as a light tan solid (18 g), m.p. 99100.8C.

EXAMPLE 7 1-Methoxy-1-methyl-3-furfu'ryl-3-(4- chlorophenyl)urea To a chilled solution of N-furfuryl-4-chloroaniline (8.0 g, 0.0386 In), triethylamine (4.04 g, 0.042 m).and benzene was added a benzene solution of phosgene (4.15 g, 0.042 in) over a 1% hour period. The resulting slurry was refluxed about 15 minutes and filtered to remove the white solid amine hydrochloride. Stripping of solvent yielded the intermediate carbamyl chloride .as a dark oil, which was redissolved in ethanol and added dropwise to a slurry of methoxyamine hydrochloride (3.34 g, 0.04 m) and sodium carbonate (4.66 g, 0.044

m) in ethanol-water. The mixture was refluxed for about hour and then stirred overnight at room tem perature. The ethanol and some water was removed under reduced pressure and the residue extracted with benzene. This benzene solution after the usual acid/- base workup gave 1-methoxy-3-furfuryl-3-(4- chlorophenyl)urea as a crude dark oil (8 g).

This intermediate (7.0 g) was dissolved in methanol (60 ml) and to this solution was added sodium hydroxide (1.07 g) in 4 ml of water, followed by dropwise addition of dimethylsulfate (3.34 g) over a period of 5 minutes. The temperature rose to 37C., and external heating was applied to maintain 60-65C. for 1% hours. Methanol was removed under reduced pressure and the residue taken up in ether and the ethereal solution washed with 10% HCl, saturated NaHCO and water. The dark oil (6.8 g) which was isolated was found to contain unreacted starting material as well as product by n.m.r. spectroscopy. Therefore the oil was retreated as above with additional dimethylsulfate and sodium hydroxide. Similar workup gave an oil (5.8 g) which solidified. This was recrystallized from heptanelacetone to yield the product which melted at 6366C.

EXAMPLE 8 1-Methyl-3-furfuryl-3-( 3-chloro-4- methylphenyl)urea N-Furfuryl-N-(3-chloro-4-methylphenyl) carbamyl chloride (formed by reaction of the appropriate aniline with phosgene as in Example 6) g, 0.0352 m) was dissolved in 250 ml of benzene. After chilling the solu tion to 10C., excess monomethylamine was bubbled through the solution. The resulting amine hydrochloride salt was removed by filtration and the filtrate washed with 10% HCl, saturated NaHCO solution, and brine solution. Drying of the solution with MgSO, followed byremoval of solvent yielded a dark solid which was purified by recrystallization from heptane.

The yellow product (5.1 g) melted at 9l-93C.

In similar fashion the following compounds were prepared according to procedures outlined above. All products were analyzed by n.m.r. and infraredspectroscopy and found to be consistent with the pro posed structures.

EXAMPLE 9 1,1 -Dimethyl-3-furfuryl-3-( 3-trifluoromethylphenyl- )urea, amber oil, formed by reaction of dimethylamine with N-furfuryl-N-(3-trifluoromethylphenyl)carbamyl chloride.

EXAMPLE 10 l ,1-Dimethyl-3-furfuryl-3-(3-chloro-4- methylphenyUurea, m.p. 66.567.8C. prepared by reaction of dimethylamine with N-furfuryl-N-(3- chloro-4-methylphenyl)carbamyl chloride.

EXAMPLE ll 1,1-Dimethyl-3-furfuryl-3-( 3-chloro-4- methoxyphenyl)urea, m.p. 947C., prepared by reaction of dimethylamine with N-furfuryl-N-(3-chloro-4- methoxyphenyl)carbamyl chloride.

EXAMPLE 12 1,l-Dimethyl-3-furfuryl-3-( 3-chlorophenyl )-urea, amber oil, prepared by reaction of dimethylamine with N-furfuryl-N-(3-chlorophenyl)carbamyl chloride.

EXAMPLE l3 1-Methyl-3-furfuryl-3-(4-chlorophenyl)urea, m.p. 94-96C., prepared by reactionof N-furfuryl-4- chloroaniline with methyl isocyanate.

EXAMPLE 14 1-Methyl-3-furfuryl-3-(3-trifluoromethylphenyl- )urea, viscous oil, prepared by reaction of N-furfuryl-3- trifluoromethylaniline with methyl isocyanate.

EXAMPLE l5 l-Methyl-3-furfuryl-3-(3-chlorophenyl)urea, m.p. 60-63C., prepared by reaction of monomethylamine with N-furfuryl-N-(3-chlorophenyl) carbamyl chloride.

EXAMPLE 16 1,1-Dimethyl-3-tetrahydrofurfuryl-3-(4- chlorophenyl)urea, viscous brown oil, prepared by reaction of dimethylamine with N-tetrahydrofurfuryl-N- (4-chlorophenyl)carbamyl chloride.

EXAMPLE l7 1,l-Dimethyl3-tetrahydrofurfuryl-3-(3- chlorophenyhurea, brown oil, prepared by reaction of dimethylamine with N-tetrahydrofurfuryl-N-(3-chlorophenyl)carbamyl chloride.

EXAMPLE l8 l,1-Dimethyl-3-tetrahydrofurfuryl-3-(3,4- dichlorophenyl)urea, b.p. 80C./0.65 mm, prepared by reaction of dimethylamine with N- tetrahydrofurfuryl-N-(3,4-dichlorophenyl)carbamyl chloride.

EXAMPLE l9 l,1-Dimethyl-3-(a-methylfurfuryl)-3-(4 chlorophenyl)urea, b.p. l46-54C./0.2 mm., prepared by reaction of dimethylamine with N-(amethylfurfuryl)-N-(4-chlorophenyl)carbamyl chloride.

EXAMPLE 2O 1,1-Dimethyl-3-furfuryl-3-(4-bromophenyl)-urea, m.p. 98.5-100C., prepared by reaction of dimethylamine with N-furfuryl-N-(4-bromophenyl)-carbamyl chloride.

EXAMPLE 21 1,l-Dimethyl-3-(tetrahydro-2-pyranylmethyl)-3-(4- chlorophenyl)urea, amber oil, prepared by reaction of dimethylamine with N-(tetrahydro-Z-pyranylmethyl)- N-(4-chlorophenyl)carbamyl chloride.

The compounds of this invention can be applied in various ways to achieve herbicidal action. They can be applied, per se, as solids or in vaporized form, but are preferably applied as the toxic components in herbicidal compositions comprising the compound and a carrier. The compositions can be applied as dusts, as liquid sprays, or as gas-propelled sprays and can contain, in addition to a carrier, additives such as emulsifying agents, binding agents, gases compressed to the liquid state, odorants, stabilizers, and the like. A wide variety of liquid and solid carriers can be used. Nonlimiting examples of solid carriers include talc, bentonite, diatomaceous earth, pyrophyllite, fullers earth, gypsum, flours derived from cotton seeds and nut shells, and various natural and synthetic clays having a pH not exceeding about 9.5. Nonlimiting examples of liquid carriers include water, organic solvents such as alcohols, ketones, amides and esters; mineral oils such as kerosene, light oils, and medium oils, and vegetable oils, such as cottonseed oil.

In practice, herbicidal application is measured in terms of pounds of herbicide applied per acre. The compounds of this invention are effective herbicides when applied in herbicidal amounts, i.e., at rates between about 0.2 pounds and about 10 pounds per acre.

HERBICIDAL EFFECTIVENESS Method of Propagating Test Species Crabgrass: Digitaria sanguinalis Johnson grass: Sorgum l-Ialepense Barnyard grass: Echinochloa crus-galli Amaranth pigweed: Amaranthus retroflexus Turnip: Brassica sp.

Cotton: Gossypium hirsutum var. DPL smooth leaf.

Corn: Zea Mays var. Golden Bantam.

All crop and weed species are plantedindividually in 3 inch plastic pots containing potting soil. Four seeds of each of corn, cotton, and snapbeans are seeded to a depth equal to the diameter of the seed. All other species are surface seeded and sprinkled Herbicidal testing of the compounds of Examples through 21 and of the comparative compounds showed the results set forth in Table I. The plants are tableted using the following abbreviations:

before treatment. 5 Planting dates for the post-emergence phase are var- C b CG f8 rass lCd so that all the seedlings Wlll reach the desired stage Johnson grass JG of development simultaneously. The proper stage of glarnyard grass 54% ornmg g ory' seedling development for treatment in the post Pigweed PW emergence phase 15 as follows: Turnip TP Cotton CT Crabgrass 2 inches in height C0"! CN Turnips l or 2 true leaves visible above V I cotyledons The rating system used 11'] 0-100 where 100 indicates Com First true leaf 1 inch in length. complete eradication (100 percentcontrol) of the test expanded cotyledons. species.

TABLE I Preemergence Postemergence Example Lbs per Number Acre CG JG BG TP PW MG CT CN CG TP CT 9 10 90 70 60 0 40 40 60 60 2 90 0 30 60 90 0 0 0 0 6O 0 I0 10 90 100 40 70 0 0 0 100 100 80 2 20 6O 20 40 0 0 0 40 90 50 ll 10 90 0 90 90 90 0 O 20 lOO 80 2 80 0 30 30 40 0 0 20 30 90 60 l2 l0 90 O 80 100 0 8O 80 2 80 0 50 50 90 0 0 20 50 90 20 l6 1O 90 50 80 90 90 5O 2O 30 40 100 80 2 0 0 20 20 O 0 O 30 I9 10 90 80 90 90 30 40 100 I00 100 2 8O 20 20 80 0 30 0 90 100 80 21 10 8O 50 40 9O 30 40 lOO I00 50 Method of Treatment Spray applications are made in a hood containing a moveable belt and fixed spray nozzle. Forpassage through the spray hood, one pot of each species (preemergence phase) is placed on the forward half of a wooden flat and one pot of established plants (postemergence phase) is placed on the rear half of the flat. Treatments are moved to the greenhouse after spraying. Watering during the'observation period is applied only by sub-irrigation.

Compounds are screened initially at a rate of application equivalent to 10 pounds per acre. Two weeks after treatment the preand post-emergence percent injury is visually rated. Subsequent testing was carried out at 2 pounds per acre.

Although the present invention has been described with preferred embodiments, it is to be understood that modifications and variations may be resorted to, without departing from the spirit and scope of this invention, as those skilled in the art will readily understand. Such variations and modifications are considered to be within the purview and scope of the appended claims.

What is claimed is:

60 1. A compound of the formula:

\CH-N CN/ R R n'" 65 wherein R is Z-furyI, Z-tetrahydrofuryl, 3,4-dihydrois 1,l-dimethyl-3-furfuryl3-(3,4-dichlorophenyl)urea.

2H-2-py y r 2-tetrahydropyranyl; R is hydrogen 4. A compound of claim 1, wherein said compound or C -C alkyl; R is hydrogen, methyl, or methoxy; is l,l-dimethyl-3-furfuryl-3-(3-trifluoromethylphenyl- R is methyl or methoxy; and R" and R""' are hy- )urea.

drogen, C -C alkyl, C -C alkoxy, C -C alkylthio, 5 5. A compound of claim 1, wherein said compound C --C alkylsulfinyl, C -C alkylsulfonyl, chloro, is l ,1-dimethyl-3-furfuryl-3-(3-chloro-4- bromo, fluoro, cyano, trifluoromethyl, nitro, phenoxy methylphenyl)urea.

or halo-substituted phenoxy. 6. A compound of claim 1, wherein said compound 2. A compound of claim 1, wherein said compound is 1 1 di th 3-f f 3 (3- h] -4 is 1,1-dimethy1-3-furfuryl-3-(4-chlorophenyl)urea. 1O methoxyphenyl) urea. 3. A compound of claim 1, wherein said compound 

1. A COMPOUND OF THE FORMULA:
 2. A compound of claim 1, wherein said compound is 1,1-dimethyl-3-furfuryl-3-(4-chlorophenyl)urea.
 3. A compound of claim 1, wherein said compound is 1,1-dimethyl-3-furfuryl-3-(3,4-dichlorophenyl)urea.
 4. A compound of claim 1, wherein said compound is 1,1-dimethyl-3-furfuryl-3-(3-trifluoromethylphenyl)urea.
 5. A compound of claim 1, wherein said compound is 1,1-dimethyl-3-furfuryl-3-(3-chloro-4-methylphenyl)urea.
 6. A compound of claim 1, wherein said compound is 1,1-dimethyl-3-furfuryl-3-(3-chloro-4-methoxyphenyl) urea. 